multiple-objects

multiple-objects

This selftest demonstrates having multiple bpf objects which each have programs which rely on a single ringbuffer.

This is accomplished via map pinning. See the ringbuffer definition:

struct {
    __uint(pinning, LIBBPF_PIN_BY_NAME);
    __uint(type, BPF_MAP_TYPE_RINGBUF);
    __uint(max_entries, 1 << 24);
} events SEC(".maps");

The LIBBPF_PIN_BY_NAME attribute instructs libbpf to pin the map to a file in the bpf file system. When subsequent bpf maps are loaded by libbpf with the same name/attribute, libbpf will automatically reuse the file descriptor and wire it up as the same underly map.